Locking Cover Assembly For Preventing Unauthorized Access To A Utility Shut Off Valve

ABSTRACT

A security cover assembly for limiting access to a utility curb box, including an elongated security screw mounted to a cover member configured to cover a curb box to project down into the curb box and suspend a clamping disc movable up and down in the curb box by rotation in either opposite direction of the security screw by use of a specially configured key. A cutout on the clamping disc perimeter allows the clamping disc to be lowered beneath a conventional fixed flange projecting from a sidewall of the curb box and rotated into alignment therewith to thereafter be clamped thereto upon rotation of the security screw to thereafter prevent rotation of the cover assembly and removal of the cover assembly. Rotation of the cover assembly in the opposite direction to align a cutout in the clamping disc with the flange allows installation and removal of the cover assembly.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of U.S. provisional patent application No. 62/315,865 filed on Mar. 31, 2016.

BACKGROUND OF THE INVENTION

The present invention concerns limiting access to a below grade shut off valve controlling a utility service to an individual customer for use by water, gas or other utilities. Such shut off valves are provided to enable utility personal to shut off service as to nonpaying customers or for servicing the plumbing connections to a customer, etc. The shut off valves are located a sufficient distance below the surface in order to avoid freeze up in the case of a water supply utility. A cover is attached to the top of a curb box located at the surface with a stand pipe extending down to a shut off valve. A pentagonal head security bolt is used to secure the cover in place, the bolt is advanced into a threaded hole formed in an integral flange projecting radially from the perimeter wall of the curb box. The special pentagonal wrench needed to remove the bolt are in very widespread use and have become easily available to the public. It is easy for a nonpaying customer to obtain such a wrench and turn the water back on. Sometimes a customer will fill the curb box and perhaps the stand pipe as will with concrete to prevent utility personnel from again shutting off the water which creates a considerable challenge to service personnel.

While more sophisticated security cover screws are now available, commercially from Bryce Fastener of Gilbert Arizona which uses a customized key mating with an annular space of a shape unique to a given utility not easily available to a member of the general public to solve the problem of the widespread pentagonal bolt head. However, the cover is still vulnerable to be pried off or broken open.

In addition, due to the typically great age of such fittings, the projecting flange normally having a hole receiving the security bolt is often damaged so that no threaded fastener can be effectively held in the threaded hole in the flange.

Another problem is that holes may be drilled into the or to the access cover itself to enable its forcible removal and thereby allow unauthorized access to the shut off valve.

It is an object of the present invention to provide an improved security locking cover assembly which is much more rugged and effective to prevent the security cover to be pried or broken off while effectively preventing unauthorized access which is more effective against unauthorized removal than the described conventional cover and security bolt arrangement, and which can be installed even if the flange hole is broken.

SUMMARY OF THE INVENTION

The above recited object is achieved by an access cover assembly for the top of a curb box which includes a cover member which can be positively held in position on the top of the curb box by a central security screw passing down through the cover member threaded and into a clamping disc, which may be thereby suspended below the cover member at a level lower than the integral flange of the curb box.

The clamping disc has a cut out matching the flange shape, and when the cut out is aligned with the flange, the clamping disc can be lowered down past the flange by rotation of the security screw to a position lying just beneath the flange. The entire cover assembly can then be manually turned to bring the clamping disc to a locking position lying beneath the flange. When the security screw is rotated in a direction to elevate the clamping disc lying beneath the flange, a clamping engagement of the disc is established against the flange, thereafter preventing any further rotation of the cover assembly as long as the security screw remains tightened this positively prevents the cover member from being removed from the top of curb box until the security screw is turned by a special key in a reverse direction so as to loosen the clamping disc from its engagement with the flange. The entire cover assembly can then be manually rotated to again align the clamping disc cut out with the flange and allow removal of the cover assembly and gain access to the shut off valve.

The clamping engagement creates a very rugged cover assembly very resistant to prying or breaking up of the cover.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial view of a cover assembly according to the invention installed on a curb box.

FIG. 2 is an enlarged top view of the cover assembly showing details of the security screw head.

FIG. 3 is an exploded pictorial view of the components of a cover assembly according to the invention.

FIG. 4 is an enlarged pictorial view from the top of a conventional curb box.

FIG. 5 is a view of the cover assembly shown in FIG. 1 looking up from a point beneath the curb box towards the under part of the cover assembly, with the cover assembly rotated to a position aligning a clamping disc included in the cover assembly to pass by the flange feature of the curb box so as to allow installation or removal of the cover assembly from the curb box.

FIG. 6 is the same view as FIG. 5 but with the cover assembly rotated to move the clamping disc beneath the curb box flange so as to enable it to be clamped against the flange by rotation of a security screw and thereby prevent rotation and removal of the cover assembly from the curb box.

FIG. 6A is the same view as in FIGS. 5 and 6, but showing a blocking structure added to the clamping disc resisting tilting of the cover assembly as otherwise might possibly happen if prying efforts were made.

FIG. 7 is a pictorial view of the cover assembly in an inverted position.

FIG. 8 is a pictorial view of the inverted cover assembly with the clamping disc removed to show other features of the cover assembly.

DETAILED DESCRIPTION

In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims.

Referring to the drawings, and in particular FIG. 1, the cover assembly 10 according to the present invention rests on a curb box 12 which typically is encased in paving as shown in FIG. 2.

The cover 16 member of the lid assembly 10 has a recess 18 formed extending into the upper surface thereof, in which the head 20 of a security screw 22 (preferably made of stainless steel) is disposed. The cover member may also be made of stainless steel to be resistant to impacts. A plastic cap 24 (FIG. 3) normally covering the recess 18 is not shown installed in FIG. 1.

The head 20 of the security screw formed with an annular space 26 formed with a pattern of features 21 which must be matched by a socket key (not shown) to be received into the annular space 26 (FIG. 2) and to be mated thereto. The exact shape is preferably customized for a given utility or a limited number of utilities. Such customized security screws and mating socket keys will not be easily available to the public.

This arrangement is available from Bryce Fastener as mentioned above.

The curb box 12 conventionally has a flange 48 integral with a side wall 13 of the curb box 12 projecting radially into the inner space defined by the curb box with a threaded hole 15 conventionally provided which receives a conventional pentagonal headed bolt (not shown).

An air vent hole 28 allows easy installation of the tight fitting cap 24.

The present invention provides a much more rugged connector of the cover to the curb box.

Referring to FIGS. 3, 7 and 8, the security screw 22 (preferably of stainless steel) have threaded body 30 which protrudes down from the underside 32 of the cover member 16, passing through a hole 34 in the cover member 16 (FIG. 3). A lock nut 36 is installed on the threaded body 30 so as to be located just below the cover member underside 32 with an interposed washer 38 preferably provided. The lock nut 36 is fixedly held on the screw body 30 so as not be advanced axially when the security screw 22 is rotated and only serves to maintain the axial position of the security screw threaded body 30 with respect to the cover member 16.

Thus, together with the head 20, the lock nut 32 acts to hold the security screw 22 in a fixed axial position in service projecting down from the underside 32 of the cover member 16. The lower end of the security screw threaded body 30 is threaded into a threaded hole 40 in a thick clamping disc 42 suspended below the cover member 16.

The clamping disc 42 is generally sized and shaped to be slidably fit into a reduced diameter lower section 44 of the curb box 12 (FIG. 4), but with an arcuate cut out 46 is provided in the clamping disc 42. The cut out 46 is matched to the shape of the integral rounded flange 48 projecting radially into the large diameter section of the interior of the curb box 12 (FIG. 4), with some clearance provided to insure free axial movement of the clamping disc 42 (FIG. 5).

An anti-rotation element comprised of a bolt 50 extends upwardly through a clearance hole 52 in the outer perimeter of the clamping disc 42 and is threaded into a threaded bore 54 extending upwardly into a first stop feature 56 integrally cast as a part of the cover member 16 normally projecting down from the underside thereof shown extending up from the inverted cover in member 16 (FIG. 8).

The first stop feature 56 has a flat side 58 which engages side 60A of the flange 48 when the lid assembly 10 is rotated in one direction, to establish a position with the cutout 46 aligned with the flange 48 (FIG. 5). This comprises an installation/removal position, allowing the cover assembly 10 to be installed or to be lifted up and out from the curb box 12 as long as the cutout 46 remains aligned with the flange 48.

A second cast in stop feature 62 (FIG. 8) has a flat side 64 which engages the side 60B of the flange 48 when the cover assembly 10 is rotated in the opposite direction, to move the clamping disc 42 to a position lying beneath the flange 48 (FIG. 6).

The security screw 22 is then rotated with the use of the special key inserted into space 26 in a direction causing the clamping disc 42 to be drawn up to be tightly engaged with the flange 48, clamping it thereto, preventing any rotation of the cover assembly 10 and thus positively preventing removal of the cover assembly 10 from the curb box 12.

Referring to FIG. 6A, a blocking structure 66 is fixed to the lower face 42A of the clamping disc 42, with a side aligned with an outer edge 68 thereof. This locates an outer edge 70 thereof immediately next to an inner wall surface 44 of the curb box 12.

The blocking structure 66 is shown as being a nut so as to conveniently allow a cap screw 50A instead of the bolt 50 to be used passing through the nut opening. However, other annularly shaped structures could be used.

Thus, a very rugged and simple curb box cover assembly is provided very resistant to breaking or prying efforts and able to remain intact in service for decades. The flange 48 is available to positively resist prying the cover member 16 off, with the bolt 50 or cap screw 50A and the blocking structure 66 also contributing to the very rugged connection between the cover member 16 and the flange 48 to be very resistant to efforts to pry or break the cover member off. The more centered location of the security screw 22 also makes prying off the cover member 16 more difficult.

A preferable additional feature is a surface hardening treatment applied to the security screw 22 and the cover member 16, making drilling thereinto extremely difficult, to effectively deter all attempts to remove the cover assembly 10 as by such drilling.

This process is commercially known as nitro carburization, and makes drilling into these components much more difficult, effectively deterring attempts at removal of the cover assembly 10 by such drilling efforts. 

1. A security cover assembly for deterring access to a utility shut off valve through an open topped curb box; said security cover assembly including a cover member configured to cover the open top of a curb box; a clamping disc held beneath said cover member by a security screw inserted in a hole in said cover member and rotatable therein while being held projecting axially down from an underside of said cover member, a lower end of said security screw received in a threaded hole in said clamping disc; said curb box provided with an integral flange radially projecting into a space defined within said curb box, said flange conventionally able to receive a conventional security bolt in an off-center threaded hole in said flange; said clamping disc formed with a cutout of a shape matching said flange shape to enable said clamping disc to move axially past said flange to a position below said flange when said cover assembly is rotated to align said cutout with said flange to allow installation and removal of said lid assembly to and from said curb box; rotation of said security screw by a key in one direction causing said clamping disc to thereafter be able to be drawn upwardly into engagement with an undersurface of said flange to create a rugged connection between said cover member and said curb box, and when rotated in an opposite direction lowering said clamping disc to be disengaged from said undersurface of said flange.
 2. The security cover according to claim 1 wherein said cover member has a pair of fixed stop surfaces formed on structure projecting down from an underside thereof located to alternatively engage a respective side of said flange by continued rotation of said cover assembly in respective opposite directions, said cutout aligned with said flange in one of rotated position to allow installation and removal of said lid assembly with one of said stop surfaces engaged with one side of said flange and said cutout misaligned with said flange when another of said stop surfaces is engaged with an opposite side of said flange to thereby prevent removal of said cover assembly when so engaged.
 3. The security cover according to claim 2 further including an anti-rotation bolt carried by said cover member and engaged with said structure having at least one of said stop surfaces formed thereon to strengthen the connection between said cover member and said clamping disc and resist forcible removal of the cover as by vandals or terrorists in addition to non-paying users of the utility.
 4. The security cover according to claim 3 wherein a blocking structure is attached to said clamping disc adjacent an edge of said clamping disk located next to an inside wall of said curb box so as to resist tilting of said cover member as caused by attempted prying open said cover.
 5. The security cover according to claim 4 wherein said blocking structure has an opening receiving said anti-rotation bolt therein. 